I'm planning to start a new dojo this autumn, called JDojo@Gbg. I was inspired by the guys at Responsive in Linköping, who I met at XP2009. They have been running a dojo for some time now, and find it is an excellent way to introduce programmers from their clients to the ideas of Test Driven Development. I think we could do with more test infected programmers about the place in Göteborg, too.
I already run a dojo as part of GothPy, and Got.rb also runs regular Kata/dojo evenings, but because those programming languages are not mainstream, many developers wouldn't consider coming along. That is why the new dojo is explicitly going to use Java, or at least, the JVM platform.
I'm thinking about what Katas we are going to tackle at the new dojo, and last night I had a go at KataFizzBuzz in Java. It is an extremely simple problem to solve, and initially I thought it was too easy to be a Kata actually. Then at agile2008 I was looking around for a Kata that Michael Feathers and I could perform in 4 minutes for the "Programming with the Stars" competition, and it seemed to fit the bill. I was quite pleased we got done in that short amount of time (in python of course :-)
A couple of people have commented that this Kata is actually quite good for teaching TDD, just because it is so simple to solve. People are forced to think about TDD instead of the problem. It can easily be made more interesting by adding new requirements too. So I think I might try it out at JDojo@Gbg.